#!/bin/sh

[ "$(uci get network.globals.ula_prefix)" != "auto" ] && exit 0
# Sometimes results are empty, therefore try until it works...          
local r1 r2 r3
while [ -z "$r1" -o -z "$r2" -o -z "$r3" ]; do
	r1=$(printf "%02x" $(($(</dev/urandom tr -dc 0-9 | dd bs=9 count=1) % 256)))
	r2=$(printf "%01x" $(($(</dev/urandom tr -dc 0-9 | dd bs=9 count=1) % 65536)))
	r3=$(printf "%01x" $(($(</dev/urandom tr -dc 0-9 | dd bs=9 count=1) % 65536)))
done

uci -q batch <<-EOF >/dev/null
	set network.globals.ula_prefix=fd$r1:$r2:$r3::/48
	commit network
EOF

exit 0